Health economic evaluation alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (E-PROSPECT): a cost-effectiveness analysis.

PURPOSE: We sought to compare the cost-effectiveness of probiotics and usual care with usual care without probiotics in mechanically ventilated, intensive care unit patients alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (PROSPECT). METHODS: We conducted a health economic evaluation alongside the PROSPECT randomized control trial (October 2013-March 2019). We adopted a public healthcare payer's perspective. Forty-four intensive care units in three countries (Canada/USA/Saudi Arabia) with adult critically ill, mechanically ventilated patients (N = 2,650) were included. Interventions were probiotics (Lactobacillus rhamnosus GG) vs placebo administered enterally twice daily. We collected healthcare resource use and estimated unit costs in 2019 United States dollars (USD) over a time horizon from randomization to hospital discharge/death. We calculated incremental cost-effectiveness ratios (ICERs) comparing probiotics vs usual care. The primary outcome was incremental cost per ventilator-associated pneumonia (VAP) event averted; secondary outcomes were costs per Clostridioides difficile-associated diarrhea (CDAD), antibiotic-associated diarrhea (AAD), and mortality averted. Uncertainty was investigated using nonparametric bootstrapping and sensitivity analyses. RESULTS: Mean (standard deviation [SD]) cost per patient was USD 66,914 (91,098) for patients randomized to probiotics, with a median [interquartile range (IQR)] of USD 42,947 [22,239 to 76,205]. By comparison, for those not receiving probiotics, mean (SD) cost per patient was USD 62,701 (78,676) (median [IQR], USD 41,102 [23,170 to 75,140]; incremental cost, USD 4,213; 95% confidence interval [CI], -2,269 to 10,708). Incremental cost-effectiveness ratios for VAP or AAD events averted, probiotics were dominated by usual care (more expensive, with similar effectiveness). The ICERs were USD 1,473,400 per CDAD event averted (95% CI, undefined) and USD 396,764 per death averted (95% CI, undefined). Cost-effectiveness acceptability curves reveal that probiotics were not cost-effective across wide ranges of plausible willingness-to-pay thresholds. Sensitivity analyses did not change the conclusions. CONCLUSIONS: Probiotics for VAP prevention among critically ill patients were not cost-effective. Study registration data www. CLINICALTRIALS: gov (NCT01782755); registered 4 February 2013.